1 // skysun.hxx -- draw a sun object
3 // Written by Durk Talsma. Originally started October 1997, for distribution
4 // with the FlightGear project. Version 2 was written in August and
5 // September 1998. This code is based upon algorithms and data kindly
6 // provided by Mr. Paul Schlyter. (pausch@saaf.se).
8 // Separated out rendering pieces and converted to ssg by Curt Olson,
11 // This program is free software; you can redistribute it and/or
12 // modify it under the terms of the GNU General Public License as
13 // published by the Free Software Foundation; either version 2 of the
14 // License, or (at your option) any later version.
16 // This program is distributed in the hope that it will be useful, but
17 // WITHOUT ANY WARRANTY; without even the implied warranty of
18 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 // General Public License for more details.
21 // You should have received a copy of the GNU General Public License
22 // along with this program; if not, write to the Free Software
23 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
33 #include <simgear/misc/fgpath.hxx>
37 // scene graph root for the skysun
40 ssgSelector *sun_selector;
41 ssgTransform *sun_transform;
42 ssgSimpleState *orb_state;
43 ssgSimpleState *halo_state;
47 ssgVertexArray *halo_vl;
48 ssgTexCoordArray *halo_tl;
61 // initialize the sun object and connect it into our scene graph
62 // root. Pass in the path to your texture directory so
63 // initialize() can find the halo.rgba texture
64 bool initialize( const FGPath& path );
66 // repaint the sun colors based on current value of sun_anglein
67 // degrees relative to verticle
68 // 0 degrees = high noon
69 // 90 degrees = sun rise/set
70 // 180 degrees = darkest midnight
71 bool repaint( double sun_angle );
73 // reposition the sun at the specified right ascension and
74 // declination, offset by our current position (p) so that it
75 // appears fixed at a great distance from the viewer. Also add in
76 // an optional rotation (i.e. for the current time of day.)
77 bool reposition( sgVec3 p, double angle,
78 double rightAscension, double declination );
83 // enable the sun in the scene graph (default)
84 void enable() { sun_selector->select( 1 ); }
86 // disable the sun in the scene graph. The leaf node is still
87 // there, how ever it won't be traversed on the cullandrender
89 void disable() { sun_selector->select( 0 ); }
95 class Star : public CelestialBody
98 //double longitude; // the sun's true longitude - this is depreciated by
99 // CelestialBody::lonEcl
100 double xs, ys; // the sun's rectangular geocentric coordinates
101 double distance; // the sun's distance to the earth
102 GLUquadricObj *SunObject;
110 void updatePosition(FGTime *t);
116 double getDistance();
122 inline double Star::getM()
127 inline double Star::getw()
132 inline double Star::getxs()
137 inline double Star::getys()
142 inline double Star::getDistance()
149 #endif // _SKYSUN_HXX_